Proposal: allow "stackalloc" class references' array when using span

[ygc369]

Currently the following code is disallowed:

span<object> arr = stackalloc object[10];

But I think that this should be allowed, stackalloc object[10] should not mean to allocate 10 objects on the stack, it should mean to allocate 10 object references on the stack (all initialized to null).
I have posted this proposal in csharplang repo(dotnet/csharplang#3294), but someone told me this is a runtime issue, because the corresponding IL instruction only supports struct now. So I think this proposal need CLR support.

[jkotas]

Related / duplicate: #25423

[ygc369]

@jkotas

Related / duplicate: #25423

I think they are different. That proposal focus on "safety", but my proposal focus on "freedom" or "flexibility".

[jkotas]

Both of the proposals are solving the same problem. #25423 has the nice property that it also solves problems with stackalloc in general.

[GSPP]

If the runtime becomes capable of stack allocating references, this should just work with the normal stackalloc keyword. #25423 would not include that work.